A Surface Structure for Broadband Microwave Absorption using Conductive Polymer Composites

This paper presents a three-dimensional surface structure for broadband microwave absorption using conductive polymer composites. The surface is a multi-resonance structure comprised of polylactic acid (PLA) polymer loaded with 3.0 wt. % carbon nanotubes (CNTs). Simulation results show that more than 97% of incident energy is absorbed within or scattered from the structured surface over a frequency range from 9 to 40 GHz. In comparison, a flat slab of an equal volume of composite material is highly reflective with less than 65 % of incident energy absorbed within the material. In addition to low reflection, the structure exhibits a shielding effectiveness of more than 26 dB, which can be further improved by increasing the thickness of the structure substrate.